Expert Insights On Treating The Wounded Charcot Foot
A: Dr. Lavery manages Charcot wounds as he manages other neuropathic ulcers and fractures. He first uses compression to reduce edema and emphasizes non-weightbearing if realistic. He then uses a total contact cast (TCC) to immobilize the foot and protect the ulcer from the forces of weightbearing. Dr. Habershaw says non-weightbearing is “the keystone” in Charcot treatment, particularly for patients with ulcers.
For acute Charcot, Dr. Karlock uses complete non-weightbearing, a below-knee fiberglass cast with close monitoring. He will also use a CROW Walker.
Dr. Habershaw emphasizes optimal wound care by ensuring adequate arterial flow, control of the infection, offloading and frequent and aggressive ulcer debridement. He also suggests appropriate consults in order to facilitate metabolic control and monitoring of cardiac function, renal disease and nutrition.
In the short term, he says nonsteroidal antiinflammatory drugs (NSAIDs) may be effective while bisphosphonates may be helpful in the long term. Dr. Lavery works closely with endocrinologists who institute bisphosphonates. Dr. Lavery adds that he will employ bone stimulators when patients meet the Centers for Medicare and Medicaid Services (CMS) criteria. Dr. Karlock likewise uses external bone stimulation.
Q: What approach do you take in the surgical treatment of these wounds/deformity? Is there any role for skin substitutes?
A: Dr. Armstrong stresses that Charcot arthropathy is “first and foremost a medical disease.” He notes that only 25 percent of people with the arthropathy need any form of surgery and two-thirds of those patients generally need exostectomies. At the Center for Lower Extremity Ambulatory Research (CLEAR), Dr. Armstrong says the group is interested in the possibilities for treatment on the medical side of the equation as well as the surgical. He says it may be useful to address the RANK-L OPG pathway with modalities like intranasal calcitonin (200 IU/day in alternating nostrils), and perhaps even TNF alpha inhibition.
However, when a patient has a profoundly deformed foot and/or ankle that will not fit in a shoe, this is an indication for reconstruction, according to Dr. Armstrong. In such cases, Dr. Armstrong has found hybrid external ring fixation “highly useful” at CLEAR.
If the patient has osteomyelitis, Dr. Habershaw opts for surgery early. He says one can efficiently diagnose osteomyelitis by combining a probe to bone test with an X-ray. He says the specificity and positive predictive value approaches 90 percent with this technique. While MRI is more sensitive and specific, Dr. Habershaw cautions that there are more false positives and the test is expensive.
When it comes to Charcot wounds, Dr. Lavery says one may consider bioengineered tissue such as Dermagraft (Advanced Biohealing), VAC therapy (KCI) and collagen matrix materials like Unite (Pegasus). He says one can use these products with offloading in a prefabricated boot such as the Aircast boot.
Q: What is your indication for exostectomy?
A: Before considering surgical reconstruction, Dr. Lavery waits until the acute phase of the process ends. As he says, the goal of therapy is to get a functional plantargrade foot via the least invasive means.
“If we catch these injuries early enough, often a simple exostectomy is all that is required,” he says. “If there is a more severe deformity, the surgical plan obviously becomes more involved.”
In most cases of a chronic, stable Charcot midfoot deformity, Dr. Karlock says one can use a simple exostectomy along with Achilles tendon percutaneous lengthening. Otherwise, he says Charcot reconstruction may be indicated.